For his Nimbus series, Dutch artist Berndnaut Smilde creates clouds in empty gallery settings. They are short-lived, but damned lovely. More images at Smilde's site and you can see a video of the cloud-making over at the Washington Post. (Thanks, Lindsay Winterhalter!)
David Pescovitz is Boing Boing's co-editor/managing partner. He's also a research director at Institute for the Future. On Instagram, he's @pesco.